Zoom in on map as much as possible, click until it allows you to.
However, CV's that are real close to town, in my experience, don't spawn LVT's that close to the town, they can, but not usually. There was one base I found where if you put the CV on the other side of the island, instead of the obvious and logical choice, LVT's spawn in on land and just a couple hundred yards from the town's road. That one is close enough to drop troops upon spawning...YMMV